Types of Bladder Cancers
Superficial Transitional Tumors | Invasive Transitional Tumors | Other Types
Transitional cell or urothelial carcinoma is the most common type of bladder cancer, accounting for more than 90% all bladder cancers. Urothelial carcinomas are separated clinically into superficial tumors and muscle invasive tumors.
SUPERFICIAL BLADDER CANCER
Superficial tumors are defined as tumors that either do not invade, or those that invade but stay superficial to the deep muscle wall of the bladder. At initial diagnosis, 70% of patients with bladder cancers have superficial disease.
Tumors that are clinically superficial are composed of three distinctive pathologic types:
1) Non-invasive papillary urothelial carcinoma:
The majority of superficial urothelial carcinomas present as noninvasive (does not invade underlying tissue), papillary (finger-like projections) tumors
(pathologic stage pTa). 70% of these superficial papillary tumors will recur over a prolonged
clinical course, causing significant morbidity. In addition, 4-8% of these papillary lesions
will eventually progress to invasive carcinomas. These tumors are pathologically graded as
either low malignant potential, low grade or high grade. High grade tumors have a higher risk
2) Flat urothelial carcinoma in situ (CIS):
Flat urothelial carcinoma in situ or CIS (pathologic stage pTis) are highly aggressive lesions
and progress more rapidly than the papillary tumors.
3) Superficially invasive urothelial carcinoma:
A minority of tumors invade only superficially into the connective tissue (lamina propria) of the bladder (pathologic stage pT1); these tumors recur 80% of the time, and eventually invade the detrusor muscle in 30% of cases.
MUSCLE INVASIVE BLADDER CANCER
Approximately 30% of urothelial carcinomas invade the detrusor muscle (pathologic stages pT2-pT4) at presentation. These cancers are highly aggressive. After bladder cancer invades the muscular layers of the bladder wall it may spread by way of the lymph and blood systems to invade bone, liver, and lungs.
Infiltrating high grade urothelial carcinoma, seen in muscle and fat
OTHER TYPES OF BLADDER CANCERS
Tumors other than transitional cell carcinoma are rare and include:
It is important to distinguish these cancers from usual transitional cell carcinoma, since their treatment and prognosis are different.
- small cell carcinoma,
- squamous carcinoma,
- leiomyosarcoma (a tumor arising from smooth muscle),
- lymphoma (a tumor that usually arises in the lymph nodes),
- malignant melanoma (a tumor that usually arises from the skin)